Ais where one network ends and another begins.

A demarc is where one network ends and another begins. Demarc stands for demarcation point. It is the physical point at which the public network of a telecommunications company ends and the private network of a customer begins.

However, the distinction between where one category of network begins and another ends is sometimes blurry.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

the answer is c on e2020, bud.